Electrical connector contact crimping tool



NOV. 28, 1967 J. E. MORRIS ELECTRICAL CONNECTOR CONTACT CRIMEING TOOLJAMES E. N10/221s. BY ai W KM A T TOIZNE Y.

ELECTRICAL CONNECTOR CONTACT CRIMPING TOOL Original Filed Aug. 27, 1958l 3 Sheets-Sheet 2 lliilHln INVENTOR JAMES E. MORRIS fm/ da,

ATTORNEY Nov. 2s, 1967 J. E. Mop-ms 3,354,692

ELECTRICAL CONNECTOR CONTACT CRIMPING TOOL Original Filed Aug. 27, 19585 Sheetsheet 5 1N V EN TOR. JA MES E Mom/5.

A T TOQNE Y United States Patent O 3,354,692 ELECTRECAL CONNECTR CONTACTCRIMPING TL .lames E. Morris, Fort Worth, Tex., assigner to GeneralDynamics Corporation (Convair Division), San Diego, Calif., acorporation of Delaware Application Feb. 9, 1962, Ser. No. 172,195,which is a division of application Ser. No. 757,514, Aug. 27, 1958, nowPatent No. 3,159,511, dated (let. 23, 1962. Divided and this applicationDec. 31, 1964, Ser. No. 422,686

5 Claims. (Cl. 72-402) ABSTRACT OF THE DISCLQSURE This connectorcrimping tool has a ratchet that holds the handles of the tool inposition during closure until the handles 'have been completely closed.This assures complete crimping of each connector. An overload releasedevice or a clutch limits the amount of crimping pressure applied to theconnector to compensate for complete closing of the handles in eachcrimping operation.

This application is a division of applicants co-pending application,Ser. No. 172,195 tiled Feb. 9, 1962, now Patent No. 3,172,211, whichapplication and patent was a division of application Ser. No. 757,514,filed Aug. 27, 1958, now Patent No. 3,059,511.

Heretofore crimping tools have been used for making crimps in aconnector barrel to secure it to an electrical conduct-r. This providesfor physical and electrical contact without the necessity of soldering.However, care must be exercised to insure that a crimp of sufficientdepth has been made to prevent accidental disengagement of the connectorwith the conductor. Also, if excessive pressure is applied, theconnector barrel becomes distorted and its walls may become cut orbroken. Since the connector has a barrel portion to receive theconductor and a pin portion extension which will not receive theconductor, the position of the crimp along the connector axis must beaccurate in order to insure crimping action with the conductor.Additional crimping of the connector to the insulation on the conductorfor greater strength is sometimes desirable, requiring a second crimpingspaced along the connector axis from the rst crimp. While a lengthadjustment attachment for crimping tools is currently available, itrequires that a connector well nut be manually adjusted until thecenterline of the nut is properly set. This requires continuousadjustment in placing more than one crimp axially along the connector.

The -connector contact crimping tool comprising the present inventionprovides for a ratchet mechanism to prevent withdrawal of the connectorfrom the punch holder until the handles 0f the tool have been completelyclosed to insure suicient crimping action regardless of the size of thewire and connector being crimped. An overload release mechanism isprovided to limit the crimping pressure applied against the connector sothat excessive pressure will not break, cut or unduly distort theconnector, irrespective of its size. This is done by stopping furtherinward movement of the punches against the connector with continuedinward movement of the handles. A depth selector with a positive stop isprovided to accommodate various lengths of connector pins and barrels.For connectors requiring a secondaxial crimp, a trigger mechanism isprovided to readily permit a positive predetermined axial spacing of thesecond crimp from the lfirst. Once the tool is set for crimping of acertain depth no further adjustment is necessary and connectors PatentedNov. 28, 1967 ICC and conductors may be crimped together in a speedymass production manner without adjustment to provide for their size.

lt is therefore an object of the present invention to provide for a newand improved crimping tool.

Another object is the provision of a crimping tool which automaticallyapplies a uniform pressure to connectors and conductors irrespective oftheir various sizes.

Another object is the provision of a crimping tool wherein apredetermined minimum crimping pressure must be applied before the toolpunches may be withdrawn from contact with the connector being crimpedto its associated conductor.

Another object is the provision of a crimping tool wherein lexcessivepressure will operate an overload release mechanism to prevent crimpingtoo deeply, thereby cutting, ybreaking or unduly distorting theconnector being crimped.

Another object is the provision of a crimping tool having a plurality ofquickly adjustable positive stops for axially positioning the crimpingof a connector at predetermined distances from its tip.

Another object is the provision of a crimping tool having a stop releaseto permit the crimping of a connector in axial spaced relation from afirst crimp.

Another object is the provision of a crimping tool which automaticallyapplies a pressure within predetermined minimum and maximum limits toall sizes of connectors and conductors within wire sizes #28 through #10without manual adjustment for crimping indentations.

Other objects and features of the present invention will be readilyapparent to those skilled in the art from the following specication andappended drawings wherein is illustrated a preferred form of theinvention, and in which:

FIGURE 1 is a side elevational view with portions thereof broken away tobetter illustrate tool operation,

FIGURE 2 is an elevational view of the top handle before assembly withthe bottom handle and with a side plate removed,

FIGURE 3 is an elevational view ofthe bottom handle with rack attached,

FIGURE 4 is a perspective view of the overload release plate,

FIGURE 5 is atop plan View showing the depth selector mounting, and fFlGUR-E 6 is an exploded perspective view of the depth selectormechanism. y

This invention relates generally to an improved crimping tool of thetype having two relatively movable handle members 11 and 12 adapted tobe pivotally connected at one of their extremities. Handle member 11 isgenerally U-shaped in section formed by a Vbody portion 13 and a pair ofside plates 14, 16 which have enlarged sections 17 at the pivotalextremity. These plates have aligned open ings 18 for receiving theconnector to be crimped. Slotted openings 19 are arranged symmetricallyabout and spaced radially from the central opening 18 and are designedto accommodate fastening units 21 such as bolts, rivets or the like whenthe component parts of the tool are assembled. Handle member 12 has astructural conguration similar to that of handle member 11 except thatit is preferably constructed of solid material, such as cast iron forexample, and its enlarged extremity 22 is adapted to lit between plates14, 16. This enlarged extremity 22 has an enlarged opening 23 whosecenter is in axial alignment with the center of opening 18 in the plates14, 16. This opening 213 in handle member 12 has a series of camsurfaces 24 about its periphery.

A cylindrical punch holder 26 is adapted to rotate within the enlargedopening 23.`This punch holder 26 also has a central opening 27 in axialalignment with the other opening 18 to accommodate the connectorinserted therein. Extending radially from the central opening 27 of thepunch holder 26 and intermediate the side walls thereof are a series ofpassageways 28, preferably four in number spaced at ninety degreeintervals. These passageways 28 are preferably circular in section andcontain a shoulder 29 delined by the juncture between an innerconstricted portion 31 and an outer larger portion 32. Disposed in thepassageways 28 are forming punches 33, each having an enlarged headportion 34 that engages cam surface 24 on handle member 12 and acylindrical body portion 36 integrally connected with the head portion34 and being provided with a connector engaging tip 37. A spring member38 located between the bottom surface of head portion 34 and theshoulder 29, urges the forming punch 33 into contact with the camsurface 24. It may be readily appreciated that rotation of the punchholder 26 ina clockwise direction will cause the cam surfaces 24 toforce the forming punches 33 inwardly against the action of springmember 38. The punch holder 26 is caused to rotate clockwise as handles11 and 12 are brought together because of its connection with the tophandle side plates 14, 16 and overload release plate 39 positionedtherebetween on both sides of the punch holder 26. This rotation isdirectly related to handle movement until an excessive force is applied,after which the overload release mechanism permits further handlemovement without further punch holder rotation. Overload release plate39 consists of a pair of rotatable faces 41 riveted, bolted or otherwisesecured to punch holder 26 by fastening means 21 so as to rotatetherewith and to prevent relative rotation therebetween. The two faces41 extend toward the handle ends of the tool and terminate with anintegral transverse connector 43 upon which rollers 44 ride. Fasteningmeans 21 extend outwardly from the faces 41 of the clutch plates andengage slots 19 in the top handle side plates 14, 16. Normally thefastening means 21 will engage the clockwise end 4S of the slots 19 andthe overload release plate 39 and punch holder 26 will rotate in directresponse to movement of handle 11 relative to handle 12. However, forcesin excess of the desired crimping force on the punch tips 37 permitcontinued clockwise rotation of handle 11 without further rotation ofthe punch holder 26 or clutch plates 39. When this happens the fasteningmeans 2-1 engages the counterclockwise end 47 of the slots 19.

`When a connector exerts a force against the punch tips 37, as when alarger size connector is being crimped, the frictional force betweenpunch head 34 and cam surface 24 is too great to permit further relativemovement therebetween, and prevents further rotation of the punch holder26 and overload release plate 39. This xes the position of thetransverse connector 43 upon which roller 44 is adapted to move. Theroller 44 is mounted at the pivotal connection 49 between bar 51, whichis pivotally mounted to the top handle 11 at a point 52 slightly forward(to the left as shown in FIGURE 1) of the pivotal connection 49, andaplunger 53. This plunger 53 is telescopically engageable with a sleeve54 which is pivotally seated in a socket 56 in the end of the top handle11. An overload release rentention spring 57 urges the sleeve 54 andplunger 53 apart and thus roller 44 forward to the position shown in thedrawing. This retains the transverse connector 43 in its downwardmostposition and the overload release plates 39 in clockwise position. Thefastening means 21 connecting the overload release plates 39 and punchholder 26 to the top handle side plates 14, 16 are thus retained againstthe clockwise end 48 of the slots 19, all of which is substantially asshown in FIG- URE 1. When the connector pressure against the punch tips37 execeeds a predetermined amount and the punch holder 26 and overloadrelease plates 39 cease clockwise rotation, further closing of thehandles 11, 12 may still be accomplished. This is done by the force ofthe transverse connector 43 on the overload release plates 39 againstthe rollers 44, causing rearward telescopic movement of plunger 53against the force of spring 57. This rotates bar 51 counterclockwiseabout pivot 52 to a less vertical position, permitting further closingof the handles to the position where the fastening means 21 abut thecounterclockwise ends 47 of the slots 19.

A feature of the present invention is that the handles must fully closebefore the connector being crimped can be released from the punch tips37 and withdrawn from opening 18. This insures that a predeterminedminimum crimping effect has taken place to securely connect theconnector and its conductor together. A ratchet -mechanism is providedfor this purpose. Rack 53 has an arcuate inner surface 59 with notches61 thereon and is pivotally mounted on lower handle 12. A pawl assembly62 is pivotally mounted on fastener 63 to the top handle side plates 14,16. This assembly includes a triangular pawl 64 engageable with thenotches 61 on rack 53 ,and a rearward extension 66 to which one end 67of pawl assembly positioning spring 63 is attached. This spring 68 is ofthe compression type and, having its other end 69 fastened to the upperhandle, continually urges rotation of the pawl assembly 62. When therearward extension 66 is below pivot point 63, the spring `63 urgesclockwise rotation of the assembly, freeing pawl 64 from engagement withthe notches 61. This happens only when the handles 11 and 12 arecompletely closed and pawl 64 is urged upwardly by contact with dat face71 on the closed end of rack 58. When this is done the handles may againbe separated, causing counter rotation of the punch holder 26 andwithdrawal of the punch tips 37 from engagement with the connector. Whenthe handles are separated the flat surface 72 on the open end of rack 53engages pawl 64 to cause counterclockwise rotation to lift the pawlextension 66 above pivot point 63. Spring 68 then urges furthercounterclockwise rotation to engage pawl 64 with the rack notches 61 forthe next crimping operation.

Another feature of the present invention is the novel manner in whichthe crimping indentations `are positioned along the axis of theconnector. Positive stops are provided to limit inward movement of theconnector into opening 18 for the various desired positions of theindentations along the axis. This is done with the connector depthselector mechanism 73 mounted on the other side of the opening 18 asshown in FIGURE 5. Here a knurled knob 74 is rotated until the propercolor, designating the desired length, appears in the opening 76 inhousing 77. A trigger 73, pivotally mounted on one of the top handleside plates 14, is actuated by a trigger thumb press 79 urged downwardlyby the operator to permit an additional .adjustment for a second crimpin axial spaced relation to the rst crimp. This is more fully explainedwith reference to FIGURE 6.

The depth selector mechanism 73 shown in exploded form in FIGURE 6provides for a depth selector plunger 31 with a plurality of recesses 82of predetermined depth extending from its inner lface 83. This depthselector plunger 31 rotates about plunger pin 84 so that the selectedrecess will become aligned with opening 18, shown in FGURE 1, to receivethe connector to be crimped. The depth of the selected recess determineshow far the connector may be inserted, which in turn determines theaxial spacing of the crimping indentations on the conductor. The plunger81 consists of a cylinder having flats 86 on four sides to provideindices for alignment of the recesses 82 with the connector opening 1S.These ilats are also color coded with proper nomenclature on the outsideof the depth stop housing 77 to identify the type of connector to beused for the various positions of the plunger 61. The colored ats may beseen through a suitable opening 76 in the housing 77.

A depth selector plunger guide 87 retains the plunger 81 in its selectedposition. This guide is preferably of cylindrical configuration and ismounted on the tool in.

such manner that a central opening 88 in the guide is in axial alignmentwith the connector opening 18, shown in FIGURE 1. A transverse keyway 89extends across the outer portion of the guide to receive the depthselector plunger 81 in non-rotatable condition, the keyway walls 91being spaced substantially the thickness of the plunger 81 betweenopposing tlats 86. The guide 81 is counterbored on its inner surface 92to receive a plunger pin trigger plate 93 for axially spacing a secondcrimp as will be more fully described. A suitable aperture 94 spacedfrom the central opening 88 in the selector plunger guide 87 is for thepurpose of receiving the depth selector plunger pin 84 for pivotal andaxial movement. A selector knob 74 is engageable through oifset opening96 in the face of the stop housing 77 with the stem 97 on the outersurface of the plunger 81. A spring 98 over the stem 97 abuts the outersurface of the plunger 81 and the inner wall of the housing 77 to urgethe plunger 81 into the keyway 89 in the plunger guide 87 and theplunger pin 84 into contact with the outer surface of trigger plate 93.To make the proper depth selection the knob 74 is pulled outwardly tofree the plunger 81 from engagement with the keyway 89. The knob 74 isthen rotated (pin 84 in aperture 94 is in axial alignment with the knob74) until the proper color appears in opening 76, whereupon the knob isreleased and spring 98 again seats the plunger 81 in keyway 89 toprevent further rotation.

The trigger 78 and trigger plate 93 provide for axial spacing of asecond crimp as in the case of crimping coaxial cable wherein it isdesired to crimp the connector to both the conductor and the insulatorportion. The trigger plate 93 consists of a circular disc with a hole101 in the center and a wedge-shaped cut 102 radiating out from thehole. A small aperture 103 is placed the same distance from the centeras the pin receiving aperture 94 in the plunger guide 87. Trigger tip104 fits within the wedge-shaped cut 102. A suitable recess 106 isprovided in the plunger guide 87 to permit movement of the trigger tip104 therein for aligning aperture 103 in the trigger plate 93 with theaperture 94 in the plunger guide 87 to permit the plunger pin 84 to beurged therein by spring 98. This moves the connector in an axialdirection in an amount equal to the thickness of the trigger plate 93 sothat a second crimp may be made. As previously pointed out withreference to FIGURE 5, the trigger 78 is pivotally mounted and actuatedby pressing the trigger thumb press 79 downwardly to rotate the triggerplate 93 until its aperture 101 is in alignment with the aperture 94 ofthe plunger guide.

While certain preferred embodiments of the invention have beenspecifically disclosed, it is understood that the invention is notlimited thereto as many variations will be readily apparent to thoseskilled in the art and the invention is to be given its broadestpossible interpretation within the terms of the following claims.

I claim:

1. Means for assuring a predetermined minimum crimping action has beenapplied to a connector comprising a crimping tool having handles foreifecting crimping upon closure thereof, ratchet means interconnectingsaid handles, said ratchet means permitting closure of said handles butnot opening thereof until said handles have been completely closed, saidratchet means permitting opening of said handles upon complete closurethereof, said ratchet means comprising a rack mounted on one of saidhandles with notches on the surface thereof and an abutting face at eachend of said notches, a pawl assembly pivotally mounted on the other ofsaid handles and having a pawl engageable with said notches and saidabutting faces, said pawl being pivotally disengaged from said notchesupon abutment with one of said faces, resilient means maintaining saidpawl out of engagement with said notches until said pawl abuts the otherof said faces, said resilient means thereafter maintaining said pawl inengagement with said notches until said pawl again abuts said one ofsaid faces.

2. Means for assuring a predetermined minimum crimping action has beenapplied to a connector comprising a crimping tool having handles foreffecting crimping upon closure thereof, ratchet means interconnectingsaid handles, said ratchet means permitting closure of said handles butnot opening thereof until said handles have been completely closed, saidratchet means permitting opening of said handles upon complete closurethereof, said ratchet means comprising an arcuate rack mounted on one ofsaid handles with notches on the inner surface thereof and an abuttingface at each end of said notches, a pawl assembly pivotally mounted onthe other of said handles and having a pawl engageable with said notchesand said abutting faces, said pawl as` sembly having an extensionrearwardly of said pivotal mounting, resilient means urging saidextension forwardly, one of said abutting faces contacting said pawl tomove said extension upwardly to cause counterclockwise rotation of saidassembly by said resilient means to free said pawl from engagement withsaid notches, the other of said faces contacting said pawl to move saidextension downwardly to cause clockwise rotation of said assembly bysaid resilient means to urge said pawl into engagement with saidnotches.

3. Overload release means for preventing crimping pressures greater thana predetermined amount to be exerted on a connector being crimped byinwardly moving punches thereon, said means comprising an overloadrelease plate releasably rotatable with one of said handles and operableto urge inward movement of said punches upon rotation of said plate,compression means releasably connecting said overload release plate tosaid handle whereby said handle may be moved without further rotation ofsaid overload release plate when said crimping pressure on saidconnector has exceeded a predetermined amount to thereby limit furtherinward movement of said punches.

4. Overload release means for preventing crimping pressures greater thana predetermined amount to be exerted on a connector being crimped bymoving punches thereon, said means comprising an overload release platereleasably rotatable with one of said handles and operable to urgeinward movement of said punches upon closing of said handles, saidoverload release plate ceasing rotation when said crimping pressure onsaid connector has exceeded a predetermined amount to limit furtherinward movement of said punches, means releasably connect'mg saidoverload release plate to said handle comprising a bar pivotallyconnected to said handle and eX- tendmg downwardly, compression meansyieldably urging said bar forwardly into operable engagement with saidplate to thereby urge rotation of said overload release plate with saidhandle, sand compression means permitting rearward pivoting of said barupon non-rotation of said overload release plate to thereby permitclosure of said handle.

5. Overload release means for preventing crimping pressures greater thana predetermined amount to be eX- erted on a connector being crimped byradially moving punches thereon, said means comprising an overloadrelease plate releasably rotatable with one of said handles and operableto urge inward movement of said punches upon rotation of said plate,compression means releasably connecting said overload release plate tosaid handle whereby said handle may be moved without further rotation ofsaid overload release plate when said crimping pressure on saidconnector has exceeded a predetermined amount to limit further inwardmovement of said punches, said compression means comprising a barpivotally connected to said handle and adapted to extend downwardly andslightly rearwardly, a telescopic plunger pivotally :onnected to saidbar and adapted to resiliently urge said bar forwardly into engagementwith said overload release plate to thereby urge rotation of saidoverload release plate with said handle, said plunger permittingrearward pivoting of said bar upon non-rotation of said overload releaseplate to thereby permit closure of said handle.

i *e References Cited UNITED STATES PATENTS 8/1965 Holmes et al. 72-4108/1965 Holmes et al. 72-410 RICHARD I. HERBST, Primary Examiner.

R. D. GREFE, Assistant Examiner.

1. MEANS FOR ASSURING A PREDETERMINED MINIMUM CRIMPING ACTION HAS BEENAPPLIED TO A CONNECTOR COMPRISING A CRIMPING TOOL HAVING HANDLES FOREFFECTING CRIMPING UPON CLOSURE THEREOF, RATCHET MEANS INTERCONNECTINGSAID HANDLES, SAID RATCHET MEANS PERMITTING CLOSURE OF SAID HANDLES BUTNOT OPENING THEREOF UNTIL SAID HANDLES HAVE BEEN COMPLETELY CLOSED, SAIDRATCHET MEANS PERMITTING OPENING OF SAID HANDLES UPON COMPLETE CLOSURETHEREOF, SAID RATCHET MEANS COMPRISING A RACK MOUNTED ON ONE OF SAIDHANDLES WITH NOTCHES ON THE SURFACE THEREOF AND AN ABUTTING FACE AT EACHEND OF SAID NOTCHES, A PAWL ASSEMBLY PIVOTALLY MOUNTED ON THE OTHER OFSAID HANDLES AND HAVING A PAWL ENGAGEABLE WITH SAID NOTCHES AND SAIDABUTTING FACES, SAID PAWL BEING PIVOTALLY DISENGAGED FROM SAID NOTCHESUPON ABUTMENT WITH ONE OF SAID FACES, RESILIENT MEANS MAINTAINING SAIDPAWL OUT OF ENGAGEMENT WITH SAID NOTCHES UNTIL SAID PAWL ABUTS THE OTHEROF SAID FACES, SAID RESILIENT MEANS THEREAFTER MAINTAINING SAID PAWL INENGAGEMENT WITH SAID NOTCHES UNTIL SAID PAWL AGAIN ABUTS SAID ONE OFSAID FACES.